为了实现基于可调谐激光吸收光谱技术的高检测灵敏度、低功耗、小型中红外痕量气体传感器设计, 结合锑化镓(GaSb) ICL和紧凑型多反射气体吸收气室(MPC)研制了基于不同结构传感光学核的两个小型TDLAS传感系统。两个传感光学核的总功率消耗为3.7 W, 并通过探测甲烷(CH4)和甲醛(CH2O)分别验证了双层结构和单层结构系统的性能。实验结果表明: CH4和CH2O系统的检测灵敏度分别为5.0 nL/L和3.0 nL/L, 测量精度分别为1.4 nL/L和1.0 nL/L。此外, 相同配置情况下将两种结构系统应用于甲、乙烷(C2H6)同步检测, 通过对校园环境中甲、乙烷进行连续66 h的监测试验, 验证了设计的紧凑型中红外痕量气体检测系统能够稳定有效地工作, 基本满足目前民用气体测量的稳定可靠、精度高、抗干扰能力强等要求。

Two compact Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor systems were developed based on different structural optical cores. The two optical cores combine two recent developments; gallium antimonide (GaSb)-based ICL and a compact multipass gas cell (MPC), with the aim of developing a compact TDLAS-based sensor for mid-IR gas detection with high detection sensitivity and low power consumption. The two-floor structure sensor was used for methane (CH4) measurements and the single-floor structure sensor was used for formaldehyde (CH2O) concentration measurements, with the two optical sensor cores consuming 3.7 W of power. Detection limits of ~5 nL/L and ~3 nL/L with measurement precisions of ~1.4 nL/L and ~1 nL/L were achieved for CH4 and CH2O concentration measurements, respectively. In addition, the two-structure system was used for CH4 and C2H6 detection under the same conditions over a period of 66 h campus. The results show that the sensors worked steadily and effectively. They can satisfy the system requirements of non-contact, online, real-time, high-precision, and rapid signal acquisition, as well as strong anti-jamming and high stability.